1. Field of the Invention
The present invention relates to a medicated plaster, more particularly to a medicated plaster which is convenient to use.
2. Description of the Related Art
Medicated plasters are generally oil-based medicated plasters or water-based medicated plasters. FIG. 1 illustrates a conventional oil-based medicated plaster which includes a base sheet 11 formed from a non-woven fabric, and a layer of medicinal paste 12 applied on the base sheet 11. A cover sheet 13 is provided releasably on the layer of medicinal paste 12 for covering the same. The medicinal paste 12 is typically prepared by mixing a medicinal substance with a rubber, a resin, and an organic solvent. The layer of medicinal paste 12 is relatively sticky, and can be attached firmly to the skin of a person. The cover sheet 13 is made of paper or plastic, such as PET, and is treated with a release agent. The cover sheet 13 prevents different parts of the layer of medicinal paste 12 from sticking together, and prevents dissipation of the medicinal substance. In use, the cover sheet 13 is removed to expose the layer of medicinal paste 12, which is then attached directly on the skin of the person. However, the medicated plaster covers the pores of the skin, and prevents the discharge of sweat from the pores of the skin, thereby resulting in discomfort to the skin of the user. In addition, when the medicated plaster is removed from the skin, it is likely that hairs on the skin of the user are removed together with the medicated plaster. Therefore, the oil-based medicated plaster unavoidably causes discomfort and pain to the user during use.
Referring to FIG. 2, a conventional water-based medicated plaster includes a medicated piece 15 and an adhesive piece 14. The adhesive piece 14 includes a base sheet 141 made of a non-woven fabric and applied with an adhesive layer 142, and a cover sheet 144 having a release surface 143 facing the adhesive layer 142 and treated with a release agent. Prior to use of the medicated plaster, the cover sheet 144 is laid on the adhesive layer 142 for covering the same, as shown by the phantom lines in FIG. 2. The medicated piece 15 includes a support layer 151 formed of a non-woven fabric, a medicated composition layer 152 applied on the support layer 151, and a waterproof protective layer 153 disposed on the medicated composition layer 152 for covering the same. In order to prevent the medicated composition in the medicated composition layer 152 from permeating into the adhesive layer 142 to undesirably decrease the adhesive strength of the adhesive layer 142, the medicated piece 15 and the adhesive piece 14 are packed separately in different inner bags, which are then received in an outer bag. In use, the inner and outer bags are each opened to permit joining of the medicated piece 15 to the adhesive piece 14 by removing the cover sheet 144 from the adhesive piece 14 to expose the adhesive layer 142, and attaching the support layer 151 of the medicated piece 15 to the adhesive layer 142. The adhesive layer 142 has a size larger than that of the medicated piece 15 such that the medicated piece 15 can be adhered to a central portion of the adhesive layer 142 to expose a peripheral portion of the adhesive layer 142 around the medicated piece 15. Finally, the protective layer 153 is removed to permit attachment of the medicated plaster to the skin of the user. The water-based medicated plaster is found to be more comfortable to the skin of the user. However, as the joining of the medicated piece 15 to the adhesive piece 14 involves complicated procedures, the conventional water-based medicated plaster of FIG. 2 is not convenient to use, especially for an old person or a person who is injured at certain body parts. Therefore, the conventional medicated plasters of FIGS. 1 and 2 are not satisfactory.